Dynamometer



, Dec. 14, 1943. C@ BENNETT 2,336,838 A DYNAMOMETER A Filed May 5,- 1941 5 Sheets-Sheet 1 gpm@ iNVENToR.

Bgm/0f C55/VM??? DYNAMOMETER Filed May 5, 1941 5 sheets-Sheet 3 IN VEN-TOR.

-- 6g AUDE BfA/N577 ATTORNEY.

Dec. 14, 1943. c, C, BENNETT 2,336,838

I v DYNAMOMETER v Filed May s, 1941 5 sheets-sheet 4 61% A005 51m/V577 ATTORNEY.

1N VENTOR.

. 14, 1943. c. c. BENNETT DYNAMOMETER Filed May 5, 1941 5 Sheets-Sheet 5 l l l mvfnrvon CL @U05 C? 35A/N577 ATTORNEY.

Patented Dec. 14, 1943 iJNlTED STATES wat OFFICE 9 Claims.

rhis invention relates to dynamometers and more particularly to absorption dynamometers.

Broadly, the invention comprehends a dynamometer of the absorption type including an oscillatory case enclosing a stator and a rotor, controlled water inlets and outlets for the case and a torque arm mounted on the case and connected to a measuring instrument.

An object of the invention is to generally improve dynamometers of the absorption type.

Another object of the invention is to provide an absorption dynamometer for accurately measuring power developed by a motor.

A further object of the invention is to provide an absorption dynamometer capable of absorbing variable torque and to maintain a substantially constant torque.

Still another object of the invention is to provide an absorption dynamometer having a plurality of spaced units each having independent rotor and stator elements capable of absorbing variable torque and of maintaining substantially constant resistance over a protracted period of time.

Another object of the invention is to provide an absorption dynamometer operative to maintain a true and steady torque for substantially any desired period of time.

Yet a still further object of the invention resides in the provision of a dynamometer having a plurality of spaced substantially isolated resistance units selectively operable in unison or individually or in combination with other units to produce a desired resistance.

Still a further object of the invention is to provide a dynamometer including a torque arm operative to compound the torque so that a delicate adjustment may be readily accomplished.

Yet a further object of the invention is to provide a dynamometer having a torque arm constructed to occupy but small space and to compound the torque so as to simulate a torque arm of greater length.

Other objects and advantages of this invention will be appa-rent from the following detailed description considered in connection with the accompanying drawings, submitted for purposes of illustration only, and not intended to define the scope of the invention, reference being had .for that purpose to the subjoined claims.

in the drawings wherein similar reference characters refer to similar parts throughout the several views:

Fig. 1 is a vertical sectional View of a dynamometer embodying the invention.

Fig. 2 is a top plan view partly broken away and partly in section.

' Fig. 3 is a side elevation illustrating the 'torque arm.

Fig. a is a sectional View taken substantially on the line -l of Fig. 1, illustrating one of the end plates.

Fig. 5 is a sectional view taken substantially on the line 5-5 of Fig. 1, illustrating one of the rotor plates.

Fig. 6 is a sectional View substantially on the line 6`6 of Fig. 1, illustrating one yof the stator plates.

Fig. 7 is a sectional view taken substantially on the line iof Fig. l, showing the other end plate.

Fig. 8 is a fragmentary plan View of a spacer plate isolating longitudinally spaced sections of the dynamometer to in effect form longitudinally spaced dynamometer sections.

Fig. 9 is a plan view of a gate for the variable unit.

Fig. 10 is a plan view of the shutter for the variable unit.

Fig. 11 is a sectional view of the'gate and shutter assembly.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other vembodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

Referring to the drawings for more specic details of the invention, l0 represents a driven shaft, the torque or other characteristics of which it is desired to ascertain. The shaft l0 has keyed thereon a rotor I2 including a plurality of rotor plates I4 arranged in spaced relation to one another.

Each of the rotor plates I4 includes Aa hub V, having a bore for the reception of the shaft I9, a generally radially extending web I8 preferably centrally of the hub,v a rim 20 carried by the web, and corresponding groups of radially extending vanes 22 arranged in oppositely disposed relation to one another on the sides of the web I8.

As illustrated in the left hand portion of Fig. 1 and in Fig. 5, the vanes 22 are preferably integral with the hub l 6, web I8,1and'the rim 29, and

rstator comprises a casing or housing including corresponding oppositely disposed end plates 32 and 34 having secured therebetween as by stay Each of the spacer rings 40 encircles one of the rotor plates I4, and each of these rings has on its Y edges corresponding annular shoulders complerods 36 a plurality of separator partitions or stator plates 38, 39 and 42 alternating with the rotor plates I4. A plurality of spacer rings 4|)U alternating with the stator plates 38 and 42 and the separator partition 39Vdivides the assembly into a plurality of axially spaced chambers 44,45,

46 and 41 housing the rotor and provides suitable housings for auxiliary variable rotor plates.

The end plates 32 and 34 each includes a hub I 50 having a bore for the reception of the shaft I0. The hub has therein a journal box 52 and a suitable packing 53 in the box for inhibiting seepage of water from the case past the shaft. The packing is held against displacement by a retaining ring suitably secured in thehub.

An annular endplate 32 carried by the hub 56 at the outer edge thereof has a flange 56 provided with an annular shoulder 58 and a plurality of spaced openings 60 for the reception of the stay rods 36. The inner face of the plate 32 is dished, and formed on this face is an annular boss 62 preferably semi-elliptical in cross section and a plurality of vanes 64 formed integral with the hub and the rim and providing in conjunction with the plate and the annular boss divided pockets 66. The vanes 64 on the end plate 32 are arranged in oppositely disposed relation to the corresponding Vanes on the end plate 34.

Each of the stator plates 38, 39 and 42 includes a hub 68 for the reception of the shaft |0. A bearing 69 engages the shaft I6 and suitable packing 1| is interposed between the hub 68 and the bearing 69. The packing is held in place by suitable retaining rings 13. An annular web 16 preferably centrally disposed on the hub 68 supports a rim 12 having annular shoulders 14 on each edge thereof and spaced transverse openings 16 for the reception of the tie rods 36.

The web 16 has on its sides oppositely disposed annular bosses y1,8 and radial vanes 88 integral with the hub and rim and divided by the annular bosses so as to provide pockets 82. The vanes are inclined from the web and are reversely disposed with relation to the vanes 22on the adjacent rotor plates |4.V Y

The webs 10 ofthe stator plates 38 and 42 are each provided with radial ribs 84 and 86. One of each of the ribs 84 of the stator plates 38 and 42 are bored radially to provide water inlet passages 88 and 89 extending from longitudinally extending outlet passages 9| through the rim 12. Se-

cured to theouter end ofl inlet passages 88 and 89V are a plurality of conduits 93 and 95 respectively which if desired may each Ibe provided with shut- 01T valves. The conduits 93 and 95 are connected by suitable ttings 98 and a hose to a source of watersupply controlled as by a conventional Valve, not shown. l Y

As illustrated in Fig. 6, the other rib 86 of each of the stator plates 38 and 42 extends inwardly relative to the web 10and is bored axially to pro- Y videair intake passages 94 controlled `as by a valve 96 communicatingwiththe axially spaced chambers 44, 45, 46 and 41.

mentary to the annular shoulders 14 on the end plates and stator plates so as to interlock therewith and completely seal the case.

Each of the spacer rings 46 has an offset portion |00 provided With an outlet opening |02 having secured therein a nipple |04, connected by suitable ttings and hose to a drain with a conventional valve, not shown, interposed for control thereof.

The rotor plates i4 in the axially spaced cham- 'bers44, 45, 46 and 41 are suitably attached to the shaft i6 and are provided with suitable cooperating shields more clearly illustrated in Figs. 9 to ljl whereby the energy dissipated by any of therotors can be varied at will. If desired, one side of a rotor plate |'4 can be closed oit by a face plate |66 as illustrated at the right hand end portion of Fig. 1 and in Fig. 8 to vary the resistance of an axially spaced unit. The plate 86 may be attached to the side of the rotor plate 4 in any desired manner as by screws, rivets, welding, etc. It will also be apparent that the web I8 of one of therotor plates i4 can be positioned closer to one side to vary the energy dissipating characteristics of the unit. It will of course be understood that one side of the rotor plate c-an be inished smoothly thereby eliminating the necessity for. employing the plate |06.

The pockets 24 Vformed in the rotor plates may be covered by`a plate |68 secured thereto as by bolts lit. The plate |68 is provided with openings H2 affording communications between the associated chambers 44, 45, 46 and 41 and the pockets 24 ofthe rotor plates. 4Formed o-n the rotorv plates |68 adjacent the periphery thereof are aplurality of spaced depressions H4.

A shutter i5 lrotatable on the hub of the rotor plates has a plurality of radially extended fins ||'8 for varying the openings ||2, and a lug |25) arranged on the perimeter of one of the iins has an embossed protrusion |22 adapted to cooperate with Ythe depressions H4 to hold the shutter in adjusted position. The shutter H6 may be supported in a groove formed inthe hub in such a manner as to be rotatable thereon to lie closely adjacent the rim 26 and Vanes 22.

l The lug |26 also has a notch |24 for the reception of an adjusting tool which may be inserted through an opening |26 in the casing of the stator 26. By adjusting the shutter ||6 the communications between the chambers 44, 45, 46 andV 41 and the pockets 24 formed in the rotor Vplates I4 maybe varied to increase or decrease the resistance of the dynamometer.

A torque arm indicated generally at |48 in Fig. 3 includes a short stout arm |56 bolted or otherwise secured to the stator casing 36 for movement therewith. This arm is limited in its movement by a stop |52 secured to the free end of the arm and adapted to cooperate with a bracket |54 fn:- edly securedto a frame member |56.

The arm |56 is cut away as indicated at |58 'and |68 toreduce the weight thereof and a web |62 is formed. on the side of the arm preferably below the cutaway portion |66. suitably secured on the lower edge of the arm adjacent the free end thereof is a toothed surface |64. The bracket |54 has upon its top a toothed surface |66, and an arm |68 hason one of its ends a knife edge bearing |18 received by and adjustable on Vthe ratchet |66 and the arm |68 is retained against displacement by a set screw i12 mounted in the frame.

The arm i553 has thereon a toothed surface le arranged in oppositely disposed relation to the rato-het it on the arm 25u, and a link Il@ adand a retractile spring IS connected to the bellows as by a bracket I8@ serves to extend the 1oellows and also to return the arm lti to its retracted position, and the bellows I'l8 is connecte-t as by a iiuid pressure delivery pipe i843 to an indicating instrument, not shown, suitable to register the torque.

In a normal operation, the shaft l@ carrying the rotor I2, and supporting the stator 25 for oscillation is driven from the Crankshaft of an engine a motor, or other apparatus, the torque j' 2 or other characteristics of which it is desired to test. The shaft Ib may be connected to a tachorneter for indicatingr the speed of the shaft, and any suitable type f pressure gauge, preferably one calibrated in units of torque is connected through fluid pressure means to the torque arm M3 mounted on the casing of the stator 26.

Assuming that the dynamometer is connected to an engine and to measuring instruments as hereinabove described, the operator opens the outlet valve and closes the inlet valve, the apparatus under test is then set in motion. After operating for a suicient period of time to completely displace substantially all of the Water from the unit, the outlet valve is closed and the inlet gradually opened. The engine under test is then speeded up, and maintained at a constant rate of speed and then the intake valve is further opened gradually until the torque gauge begins to indicate the pressure developed.

When water is admitted into the casing 3S it is distributed between the stator plates 38, 3S and d2 and the rotor plates I4 and projected by centrifugal force outwardly toward the periphery of the casing. Because of the varies on the respective rotor plates and stator plates, and particularly because of their relation to one another, the'water is agitated to a very high degree.

This intensiiied turbulence of the water may result in creation of a partial vacuum in the casing and to overcome this the casing is provided with an air inlet S4. The friction between the water and the rotor and stator plates results in heating the water to a very high temperature and it is by this means that the energy development by the engine under test is absorbed by the dynamometer.

It will be understood that by adjusting the shutter H6 the axially spaced sections M, t5, 46 and 'l'l of thel dynamometer may be regulated to increase or decrease the load at the will of the operator. This means for varying the load is highly important when testing apparatus of diiferent torque and speed characteristics.

It is also to be observed that the torque arm i mounted on the oscillable casing 26 has a distinct advantage in that it can be confined in a very small space and can be so regulated or adjusted as to compound the torque and that because of its particular structure it is susceptible of delicate adjustment.

When releasing the water from the casing 26 to decrease the torque or lower the power absorption thereof a partial Vacuum may be created in the casing and in that event air is admitted through the air inlet 9d controlled by the valve 95. The load on the engine may be varied by the operator simply through manipulation of the water inlet and outlet controls of the dynamometer, and the speed of the engine may be governed by operating the engine controls, and through the medium of a definitely fixed water flow through the inlet and outlet of the various sections of the dynamometer, the heat is dissipated, permitting a continuous test over an unlimited period of time.

The load on the engine may be varied by regulating the rate of discharge of water from the various sections of the dynamometer, or by regulating the rate of admission of water into thevarious sections of the casing 25. In completing the test the engine is operated with wide open throttle and the controls of the dynamometer set so as to maintain a constant load on the engine. In this connection attention is directed to the fact that one or more of the sections dei, d5, il@ or 41 of the dynamometer can be operated while the remainder of said sections of the dynamometer are substantially inactive to produce a substantially predetermined resistance.

Under these conditions the operator takes a reading of the tachometer and of the torque gauge, and with these two factors known, the horse power of the engine may be readily computed in accordance with established practice.

While this invention has been described in connection with certain specic embodiments, the principle involved is susceptible of numerous other applications that will readily occur to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

I claim:

1. A dynamometer comprising a shaft, an oscillatory case mounted on the shaft, means including stator plates separating the space within the case into a plurality of separate axially spaced compartments, vaned rotor plates carried by the shaft and extending into each of the spaced compartments, cover plates for the rotor plates having openings therethrough, and shutters for varying the effective size of said openings.

2. A dynamometer comprising a shaft, a stator including a pair of corresponding end plates, an assembly of stator plates and spacer rings arranged in alternate relation to one another between the end plates, vaned rotor elements carried by the shaft and arranged in alternate relation to the stator plates, cover plates for the rotor elements having openings therethrough, shutters for varying the effective size of said openings, water inlet means associated with the stator plates, and water outlet means associated with the spacer rings.

3. A dynamometer comprising a stator including a case having corresponding end plates provided with hubs for'the reception of a shaft, an assembly of stator plates and spacer rings arranged in alternate relation to one another between the end plates., means for clamping the assembly between the end plates so as to seal the casing and separate the space within the casing into a plurality of axially spaced compartments, separate rotor plates carried by the shaft and extending into each of thev separate compartments, a cover plate for one of the rotor plates having openings therethrough, and a shutter for varying the effective size of said openings. 4. A dynamometer comprising a. rotor blade including a hub, a web on the hub, a rim on the Web, radial vanes on the web connecting the hub and rim, a cover plate over the radial vanes having openings therethrough, and a shutter for varying the openings.

5. A dynamometer comprising a rotor blade including a hub, a Web 'on the hub, a rim on the web, radial vanes on the web connecting the hub' andvrim, a Cover plate over the radial vanes having openings therethrough, and a rotatable shutter for varying the openings; f

6. A dynamometer comprising a rotorV blade including a hub, a Web on the hub, a rim on the web, radial vanes on the web connecting the hub and rim, a cover 'plate over the radial vanes xedly secured toV the hub and having openings therethrough, and a shutter rotatable on the hub for control of the openings through the plate.

7. A dynamometer comprising a rotor blade having pockets in one side thereof, acover plate having openings positioned adjacent the pockets, a shutter to vary the eective size of said openings, and means for varying the position of the shutter to control the entrances of the pockets.

8. A dynamometer comprising a shaft, an oscillatory case mounted on the shaft, means including stator plates separating the space Within the case into a plurality of separate axiallyspaced compartments, rotor plates having hubs xed to the shaft. radially-extended rims carried by the hubs and terminating in Webs, vanes carried by the web connecting the hub and rim to provide spaced chambers in each of said compartments, shutter means for controlling said spaced chambers, and separate manually-operable means for actuating the shutter means to vary the resistance exerted on the shaft in each of said spaced compartments.

9. A dynamometer comprising a shaft, an oscillatory case supported on the shaft, a plurality of laxially-spaced stator members carried by the case and dividing the space therein into a plurality of spaced separate compartments, separate rotor members carried by the shaft and extending into each of the compartments, each of said rotor members having radially-spaced hub and rim members interconnected by Webs, vanes carried by the webs connecting the hub and rim members to provide a plurality of chambers in each of said compartments, and manually actuated shutter means controlling said chambers to vary the resistance developed in each of said separate compartments.

CLAUDE C. BENNETT. 

